Depends on the holster. I don't don't do anything to to break them in other than wearing them in if the are for CCW.
Duty holsters such as the Safariland SS III that I use gets hosed down frequently with spray silicon and the gun inserted while it's still wet until it breaks in enough to secure the retention snaps without too much effort.
Duty holsters such as the Safariland SS III that I use gets hosed down frequently with spray silicon and the gun inserted while it's still wet until it breaks in enough to secure the retention snaps without too much effort.